Effect of Silicon on Physiological Characteristics wheat Growth under Water-Deficit Stress Induced by PEG

Abstract

Silicon is known to ameliorate the deleterious effects of drought on plant growth. We evaluated growth of wheat (Triticumaestivum L. CV. Chamran) under Water-Deficit Stress Induced by Polyethylene Glycol as affected by Si application. In this article, the effects of Si (as potassium silicate) on some parameters related to soluble protein concentration, electrolyte leakage (EL), superoxide dismutase activity (SOD) and siliconand potassium concentration leaves of wheat under 20% (w/v) polyethylene glycol (PEG-6000) simulative drought stress are investigated. PEG stress decreased the soluble protein, SOD activity and K concentration and increased El. Addition of 1.0 mM Si could partially improve the protein, electrolyte leakage and SOD activity of stressed plants. The electrolyte leakage of the leaves was markedly increased under PEG stress, whereas added silicon partially reversed this. There were significant negative regressions between electrolyte leakage and Shoot dry weight. Addition of Si obviously increased Si accumulation in the shoot. Analyses of Kconcentration, showed no accumulation of these ion in the shoot under water stress, and added Si even increased their concentrations under water stress. These results suggest that under PEG-induced water stress conditions, increase soluble protein and SOD and decrease electrolyte leakage, contributed to the improved wheat growth by silicon.